With respect to in-vehicle systems, there has been enhanced an equipment rate in vehicles of in-vehicle information devices such as car navigations, TV tuners, media players and the like. Also, in recent years, diversifications have been made in various applications for safety and security that use a kind of sensor such as a camera, an electric-wave radar or the like, so that necessary information for a driver and a fellow passenger is presented to them through a display device of the in-vehicle information device by cooperating such an application and the in-vehicle information device.
Further, since a wide variety of information becomes obtainable in association with progress of in-vehicle network technology, vehicle information can be acquired that includes information from the in-vehicle information device, in addition to basic information having conventionally been displayed in a form of vehicle meter, such as a vehicle speed, an engine revolution number, a shift state, a fuel residual amount and the like. Furthermore, with respect also to the display devices themselves, not only conventional warning indicators based on mechanical meters and LED lightings but also in-vehicle display devices using fluorescent display tubes or LED panels, have become popular. Thus, by combining them to construct an information presentation system, it is able to also display other information than the basic vehicle information. As just described, diversifications have been made also in meter display apparatuses for presentation to the driver.
In the conventional meter display apparatuses, an application for meter display generates display-screen data to thereby display it on a display device dedicated for meter display. Meanwhile, in the in-vehicle information devices, a plurality of applications individually generate respective display-screen data and any one of these data is displayed in a replaceable manner when specified through an operation by the driver or a fellow passenger or depending on the fact as a trigger that predetermined vehicle information is acquired. in this manner, conventionally, respective displays by the meter display apparatus and the in-vehicle information device are usually independent to each other.
However, in recent years, in order to diversify the presentable information to the driver and a fellow passenger, there are proposed display systems each capable of mutually replacing/combining the meter display and the display by the in-vehicle information device.
For example, in Patent Document 1, there is disclosed a display control apparatus that applies image processing, respectively, on display data for the meter generated by a graphic display controller (GDC) for a vehicle system, display data for a car navigation, a DVD playback, a TV, an audio application and the like generated by a GDC for an amenity system, and display data of a variety of sensors generated by a GDC for a safety system, to thereby display them on an LCD panel mounted in an instrument panel (hereinafter, abbreviated as “IN-PANE”).
Note that, in the display control apparatus described in Patent Document 1, the meter display data is generated by controlling the GDC using vehicle information from a powertrain-system electronic control unit (ECU) and a body-system ECU that are connected to an in-vehicle local area network (LAN). Further, image-output control data such as sizes of respective images in a meter-display screen and a screen layout thereof are transmitted from a processor mounted in the vehicle system through an in-vehicle LAN of another line than that of the ECUs. Other than this, with respect also to the amenity system and the safety system, image-output control data for the display screen generated by their respective GDCs are transmitted similarly from the processor in the amenity system and the processor in the safety system though the same in-vehicle LAN.
A micro-controller for a display platform (DPF) in the display control apparatus in Patent Document 1 evaluates the respective image-output control data and the state of the vehicle that are received through the in-vehicle LANs, to thereby respectively and properly locate the display data generated by the GDCs of the respective systems on the LCD panel of the instrument panel. In such a manner, by generating the display data for image display in a shared manner by the processors in the respective systems, the stability of screen display is improved.
Meanwhile, in Patent Document 2, there is disclosed a display system that is mounted in a drivable moving object to thereby display plural sets of information including information of the moving object, individually in the screens corresponding to the respective sets of information and provided on a plurality of display panels. In this display system, the display panels are each capable of displaying at least one screen, and there are included display screen control sections provided for the respective display panels so as to generate the display data for said at least one screen in each of the display panels, and a single display selecting section that selects the screen to be displayed on each of the display panels on the basis of the plural sets of information including information of the moving object.
Namely, in the display system in Patent Document 2, there are included a plurality of blocks each equivalent to the display control apparatus in Patent Document 1, and for example, at the front seat or rear seat side in the vehicle, each display data generated by the processors of the respective systems is displayed on each display device.
However, when the same information is to be displayed respectively on a plurality of display devices mounted in the vehicle, in many cases, this information is adequate to be displayed in each display form (display content or display method) suited to each user watching the display device.
Further, since the display form suited to the user watching the display device possibly changes depending also on a vehicle traveling condition, there may be also cases, depending on a state of that change, where the user's visibility is deteriorated, resulting in a bothersome display.